Shirt stays, garters or?

[JohhnyD]

What shirt stays do you use / recommend?

[Eclipse]

Garters - 4 is generally plenty.

[baronet68]

Neither. 

I layer my garments so that each tends to pull in the opposite direction holding the others into place, the trick being to tuck my t-shirt (smoothly) into my underwear. 

The layers at my waistline are:
Skin -> Tshirt -> Underwear -> Shirt -> Trousers -> Outside World

This method doesn't require purchasing any extra equipment and has worked for 30+ years as a cadet, in the Army, and as a Senior Member.
YMMV

[Hawk200]

Neither. 

I layer my garments so that each tends to pull in the opposite direction holding the others into place, the trick being to tuck my t-shirt (smoothly) into my underwear. 

The layers at my waistline are:
Skin -> Tshirt -> Underwear -> Shirt -> Trousers -> Outside World

This method doesn't require purchasing any extra equipment and has worked for 30+ years as a cadet, in the Army, and as a Senior Member.
YMMV

This is the simplest method, I learned it in basic.

I like this: https://www.flexbelt.net/

Not too expensive, and you don't need to do anything unusual to use it.

[PHall]

2 of the "Y" style shirt garters does the trick for me. Even if I do something radical like bend over!